Sounding line for aircraft



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UNITED STATES HENRY E. KRAMMER, OF NEW YORK, N. Y.y

SOUNDING LINE FOR AIRCRAFT.

Application led April 16, 1920. Serial No. 374,268.

The invention relates in general to a lead the obstacle which cause thesignal to funeline device for ascertaining and measuring verticaldistances and specifically relates to such a device designed to becarried on an 'aeroplane or similar' vehicle for the purpose of makingsoundings to ascertain how far the faeroplane is above the ground orWater over which it is flying.

In such devices heretofore used on ships yfor making soundings the bobor other 'weight on the end of a flexible cable has Y been permitted tofall slowly by gravityun- 1 til it strikes bottom. However, it isobvious` that should such a device be utilized on an aeroplane,frequently moving at extremely high speeds, the drag of the bob while itis passing vertically at relatively slow speed through the air wouldintroduce material errors in the indicated reading on the indicatorsregistering the amount of played out cable. This would obviously resultin serious consequences to the machine especially when flying at highspeeds and low Y altitude. j 25, Accordingly, one of the objects of theinvention is to provide va lead line device which is shot at highvelocity downwardly from the machine so as to minimize the time elementof transit and thus tend, as far as possible, to cause the cable toregister the shortest line between the aeroplane and the ground or waterover which it is flying.

I attain this invention broadly by positioning the bob deiining the endof the cable within a downwardly pointing gun so arranged that thefiring of the gun will forcibly project the bob which thus constitutes aprojectile and cause the projected bob t-o draw with it the cable,unwindi-ng from a freely turning reel and indicating the length of drawnoif cable on a suitable indicator.

Still featuring accuracy in measurements,

another object of the invention'is to provide .a simple form ofautomatically actuating signalling device which will promptly indicateto the operator the instant that the falling bob has struck an obstacle.

It can readily be appreciated that it is objectionable, if notdangerous, to have a cable from the aeroplane dragging on the groundevenfor a short period of time, and accordingly another object of theinvention is to provide a means for quickly rewinding the cable onto thecarrying reel which rewinding movement will be inauguratedinstantaneously by the contacting of the bob with tion.

Still another object of the invention is to provide means forautomatically disconnectlng the winding means from the reel when the bobhas reached its fully raised position and for reset-ting the partsautomatically in position for a quick succeeding resounding.

Various other objects and advantages of the invention will be in partobvious from an inspection of the accompanying drawings and in part Willbev more flly set forth in the following particular description of oneform of mechanism embodying my invention, and the invention alsoconsists in certain new and novel features of construction andcombination of parts hereinafter set forth and claimed.

In the accompanying drawings The figure is a single sectional view takenthrough an aeroplane structure and through a preferred embodiment of myinvention with certain parts shown in elevation and with the electricconductors shown diagrammatically. a i

In the following description and in the claims, parts will be identifiedby specific names for convenience of expression but they are intended tobe'as generic in their application to similar Vparts as the art willpermit.

There is shown an aeroplane structure 10 ofa type such as is more fullydisclosed in my copending application, Serial No. 243,- 564, filed July6, 1918. A gun 11 constitutes a part of the aeroplane structure andincludes a vertically disposed projectile guiding tube 12, into theupper end of'which is telescoped an explosive chamber 13. The lower endof the chamber 13 is formed slightly conical to receive the conical headl14 of a bob or projectile 15 which is attached to the free end of acable 16. The cable is passed through a stuffing box 17 defining theupper end of the chamber 13 and is coiled about a horizontally disposedtake up reel 18. The gun is featured by a relatively long barrel and isdirected either straight downwardly or preferably is inclined at aslight angle forwardly so as to compensate, at least to some extent, forthe air resistance introduced bythe forward drift of the 'niachineduring the two or three seconds that the projectile is in the air. isloaded with an explosive charge intro- The gun the cable thereon. Thefree end of the armaflanges 24 between which is positioned the` wound upportion of the cableio. Y* Aportion of the hub is hollow and into thehollow portion is 'telescope'd a shaft sleeve 25 iXed in the bearings 21by means of the mit 26.

The cable is wound'on the reelbymeans" of an electric motor 27 whichacts through a one-way clutch 28 and squared sha-ft 29 inserted in theadjacent end of the hub '23. The teeth 30 of the one-way clutch areAarranged so that the reel in .unwinding can turn freely without theload 'of the dead' motor and so disposed thatv when the motor isenergized it will promptly pick up lthe reel .and turn ritin theldirection `to wind ture shaft is 'provi-ded with a. squared head 31designed to be engaged by a hand crank 32, shown in dotted outline, sothat the cahle may be wound on the reel manually in case the electricalfeatures of the disclosure become inoperative `for any reason. y

An odometerl 33,401* .other measuring instrument is positioned on thebea-'ringr22 and is operatively connected tothe reel by a meshed gearedconnection`84. 'The yodometer is so organized that theplayed out lengthof the. ca-ole is indicated Ain feet or other linear units ofmeasurement.

v f There :are disclosed two lelectric circuits so" connected that themovement ofthe projec- 'tile out of 4the gun closes one circuit and theContacting of the bob with the obstacle below the machine wili-close'another circuit and the succeeding coaction of these two circuitclosers will cause thev motor to become active.

Referring irst'to the elements which go 4to make up a circuit,hereinafter identified as n a motor circuit, there is shown a sour-ce ofelectric energy' 3.5 one side of which is grounded by means of theconductor 36 on the frame of the machine. The other side leads by meansof the conductors 37l and 38 to one Vend of afpivoted switch 89,

which switch constitutes the -armature `of an electromagnet 40`hereinafter more fully described. The movement of theswitch into 7circuit closing position kis under the `influence of the electromagnetwhichV effects a closing of the circuit through a. contact 41 andconductor 42 to one side of the motor A27.

The other side ofthe motor is grounded on the machine by means of theconductor 43. `The switch 89 is provided with ya finger 44 whichvprojects through the side of the gun and into the path of the bob 14.

By this construction itis understood that the presence of the bob in thegun maintains the motor circuit opened so thaty the motor jed on thevhub oit' the reel.

is inactive as long as the bolo is in its elei Yvated position. A springpressed stop but- Y stop however is sufficiently weak to permit theswitch to be positively pushed away romfthe electrom-agnet and into acircuitv breaking position by the action of the bob on the ringer 44 andto permit the electromagnet to draw the switch int-o its circuit closingposit-ion in which positionit is held'by the button 45. 'The secondcircuit, hereinafter identifiedas the contr-ol circuit, includes aconductor 46 which leads off from the conductor `37to one side of the.electromagnet- 40, a con-ductor 47' which leads from the 'other side ofthe electromagnet to -a signalling device48,` herein shown toA be anelectric Vlight bulb, and from the electric light bulb throughv aconductor 48a, and through the shaft sleeve' 25 -to the relativelystationary elements 49 of -afrotary commutator 50. 1

The cable is' provided with two Aconductors, yone of which-51 has oneend connected to theV rotary element 50 of the commutator and the yotherconductor 52 whichis ground- 'and terminate in depending Contact Apoints53 and 54. lThe circuit is closed through The opposite or f these pointsby means oi a horizontally dis-v` f posed contact plate 55 which is heldin position spacedvbelow the contact points by means of the coii spring56.-

4-'I`helower end lof the explosive chamber i 13 'is defined by ast-opring 57 designed to have its'fiower side'engaged by a stop plate 58` andhaving a'resilient connection with the bob through the interposed spring59 soV arranged that the bob is cushioned in. moving into its elevatedposition shown in the drawings.

In operationand' assuming that the parte are in the position shown inthe drawing and that it is desired to :ascertain how far the aeroplaneis above the land or sea, the opera- Y tor hres the gun. The bob isshotdownwardly and the lcable isunwound ilom the @reel at high speed. Oniiring `theguii the operator watches the yodometer and the :dashing oftheV signal permits him to taire his reading, and he can then ignore thefurther action of the device except to load the gun iu casca succeeding`reading is desired.V y It will be appreciated that the movement of thebob out gof the path oit the iinger 44 f permits the electromagnet 40when energized '125 to draw the switch 39 into circuit closing positionengaging the contact 41 as hereinafter:

described.

The movement of the plate '55 into engagement with the ground, sea orother ob- I ject, will momentarily close the circuit .engagement withthe Contact l1 completes the motor circuitand the button 45 acts to holdthe switch in its circuit closing position. It will thus be seen thatthe signal is ffiashed the instant t-he bob strikes the obstacle and themotor will promptly begin to wind up the cable onto the reel. This willcontinue so long as the switch 89 is maintained in circuit closingposition. The movement of the bob into its final position in the gunwill act through the arm 4a to force the switch 39 into the openposition shown in the drawings and the parts are then in position readyto receive a new charge of explosive and to repeat the operationdescribed.

By means of a device of this character it is possible to take rapidlysucceeding read ings and when once inaugurated each succeeding operationis entirely automatic except for the reloading and firing. It ispossible to take rapid soundings while travelling in the dark at highspeeds and thus feel the way cautiously over strange territory. There isno-loose slack to the cable for the cable begins to re-wind the momentcontact is made with the obstacle which might otherwise hold the bob.The bob is not dragged horizontally for any appreciable distance andthere is thus eliminated the possibility of catching.

While I have shown and described, and have pointed out in the annexedclaims, certain novel features of my invention, it will be understoodthat various omissions, substr tutions and changes in the form anddetails of the device illustrated and in its operation may be made bythose skilled in the art without departing from the spirit of theinvention.

Having thus described my invention, I claim 1. In a device of the classdescribed, the combination with an aeroplane, of a. lead line mechanismmounted on the aeroplane and including a reel, a flexible cable wound onsaid reel and provided with a bob at its free end, and a. gun forprojecting the bob .with high velocity through the air relatively to thefiight of the aeroplane, and drawing the cable off said reel.

2. The combination with an aircraft of a device for measuring distancesincluding a reel having a iieXible cable wound thereon, a gun forprojecting the bob and cable with high velocity relatively to the flightof the airplane, a motor adapted to be connected to the reel to re-windthe cable thereon, signaling means, control means for the motor, circuitmeans adapted to-be closed upon impact by the bob for operating said twolast named means, and means actuable by the bob on reaching its returnposition to operate said control means whereby to open the circuit meansthroughy the motor.

3. In a device for -measuring' vertical distances from an aircraft inflight, the combination of a. reel having a flexible cable woundthereon, a gun, a projectile for the gun con-' nected to the free end ofthe cable to constitute a bob, and means for firing the gun whereby tounwind the cable with relatively highvelocity from the reel.

4. In a device of-the class described, the

combination of a supportincluding a pair of bearings, a reel including ahub journaled in one of said bearings, a cable wound on said reel andcontaining an electric conductor, power means operatively connected tosaid hub to wind the reel in one direction, a hollow shaft carried bythe other bearing and constituting a bearing for the other end of thehub, a commutator carried by the hub, a conductor connecting the rotaryelement of the commutator with the conductor in the cable and anotherconductor leading through said hollow shaft to make a sliding contactwith the commutator.

5. The combination with an air craft of a high pressure gun, a cableincluding a bob on one end thereof constituting a projectile for thegun, a reel for said cable, a motor acting on said reel for placing thebob in its raised position in the gun, and means for cushioning the bobas it is moved into position.

6. In a device of the class described, the combination with a gun, of acable including a bob on one end thereof constituting a projectile forthe gun, a reel for said cable, an electric motor acting on said reelfor placing the bob in its raised position in the gun, means forcushioning the bob as it is moved into position and a switch operativelycontrolled by the movement of the bob into its raised position tointercept the action of the motor.

7. In a device of the class described, the combination with a gun, of acable having a bob on one end thereof constituting a projectile for thegun, means for forming an electric circuit including a source ofelectric energy, a motor in said circuit for elevating the bob, and anelectromagnetical'ly controlled switch for completing the circuit, saidswitch being moved into an open position by the movement of the bob intothe gun thereby to intercept the bob lifting movement of the motor.

8. In a device oflthe class described, the combination of a cable havinga. bob on the free end thereof, a receptacle for containing the bob whenin elcvatingposition, an organization of elements for forming anelectric circuit, including a motor for elevating the bob and twocontrolling .switches arranged to close thev circ-uit through the motoi`only whenA the bob, the'otliei' switch carried bythe bob and adapted tobe moved into closed position by the Contact of the bob with an ob-y YSteele.y

9, The 'combination with an an `aircraft ofV fa ,lead line having a bobon one end, means for Projecting the bob with high Velocity relativelyto the Hight of the air omit, and

mea-ns .controlled the engagement of ythe ,bob with an obstacle forraising the bolo.

10. The kcombination with an ztrcralft of a i lea-d line having a bob onone end thereof,

means for projecting the bob with'higli vey locity relatively to theight ofthe air craft,

powel1 meansfor'misng the bob, antlmeans controlled by the respectiveterminal posi-- tions of the bob for starting and stopping .the

action of said power means.

Signed at New York city, inthe county of lNew Yorltand State of N ewYork, this 10th Y clay of April, A. D. 1.920.

' HENRY E; KRAMMER;

